This green vegetable comes into the category of healthiest plant-based foods. Besides being rich in iron, it is one of the principal resources of pigments, vitamins, minerals and phytonutrients. It is a rich source of beta-carotene, lutein, and xanthene, all of which are beneficial for eyesight. Beta-carotene is supplied to the eyes by cooked spinach. It can prevent vitamin A deficiencies, itching eyes, eye ulcers, and dry eyes.